Implantable infusion devices typically include a housing containing a medication reservoir which can be filled transcutaneously by a hypodermic needle penetrating a fill port septum. The medication reservoir is generally coupled via an internal flow path to a device outlet port for delivering medication through a catheter to a patient body site. Typical infusion devices also include a controller and a fluid transfer mechanism, such as a pump or a valve, for moving the medication from the reservoir through the internal flow path to the device's outlet port. The use of such implantable infusion devices has been well established in pain management, and therapies such as diabetes control, where a single medication is delivered to a single body site.
In other therapies, it is desirable to deliver the same medication to two different body sites, such as cisplatinum to the ovaries for ovarian cancer, either at the same rate or at different rates. In yet other therapies, there is a need to deliver two or more distinct medications to different body sites or to the same site independently. For example, with some pain management protocols, it is desirable to deliver morphine and clonidine to a patient's intrathecal site. In certain cancer therapies, it may be desirable to deliver multiple medications to multiple sites. As a further example, in diabetes therapy, insulin and glucogon may be administered sequentially to lower or to raise blood sugar respectively. 